Imprpyement in registering steam-gages



' 2Sheets--Sheet!'. J. P. HOLT.

Improvement in Registering Steam-Gauges. Ng. 129,958, Patented July30,1872.

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I IMPROVEMENT n REGISTERING STEAM-GAGES.

Specification forming partof Letters Patent No. 129,958, dated July 30, 1872 To alt whom it may concern: 7

Be it knownthat I, JOHN P. HOLT, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and Improved Steam-Gage, and I do hereby declare that the following is a full, clear,and complete descriptionthereof, reference being had to the accompanying drawing making part of the same.

Figure l' is a front view of the gage. Fig. 2 is a view of the inside, having the dial-plate removed so that the inside can be seen. 7

Like letters of reference refer to like parts in the several views.

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I also to indicate and make knownthe fact when the steam has been carried to a higher pressure than that fixed as the maximum degree that the boiler should'be allowed to carry.

Of said invention the following is a more full and complete description: i

In reference to the above-said gage I would remark that so much of the mechanism of the gage used for indicating the number ofpounds pressure that the boiler is carrying is not new, as it is the same in construction and operation as that described in the patent for steam-gage granted to me October 29, 1867 5 hence a full detailed description of that part will not be made,'but simply alluded to for a more proper understanding of the improvement attached to it.

In the drawing, Fig. 2, A represents a shell, in which the mechanism of the gage is arranged, and which consists in part of the spring B, stem (1, lever D, link E, adjustable arm F attached to the arm of the bow Gr, chain H connected to the cone on the index-spindle, coiled spring I, dial-plate, and. pointer, all of which are arranged and operated substantially as described and set forth in my patent of the date above said. In combination with the above-specified devices, and which are intended to indicate ,the pressure of steam, I have arranged to co-operate therewith a device for showing the excess of steam carried by the boiler over the prescribed maximum number of pounds, so that the inspector of boilers shall become aware of the fact and the number of times that such excess may have been indulged in. Said device consists of the following parts: J, Fig. 2, represents a plate having upturned edges a, between which is fitted loosely, so as to slide easily on the plate, a scale, J, read from the top downward. 0n the inner edge of the scale is out a series of notches, f, the

purpose of which will presently be shown. L

is a lever, pivoted at the point 0. To the inner end of said lever is pivoted apawl, M, the upper end of which is made to engage with the notches in the side of the scale J, as shown, and which is held in engagement therewith by a spring, cl, pressing upon the arm of the pawl. Between said pawl and the teeth of the scale is a spring, 0, the lower end of which is secured to the side of the plate J, whereas the upper end is made to engage the teeth of the slide immediately below the engagement thereof by the pawl, as shown in the drawing. The dotted lines f indicate a pointer or index. Said pointer is connected to a toothed wheel, c, with which is made to engage the lower end of a spring-pawl, g, whereby the wheel and index are prevented from turning backward, but does not interrupt their forward movement. Said pointer is the tell-tale pointer,

' which indicates the excess of steam that may have been carried by the boiler above a certain number of pounds. Said pointer and wheel are not fixed to the spindle, but simply revolve permanent manner, and which pointer is the I one to indicate the steam-pressure. The lever L above referred to is attached to the adjustable arm F by a slot in the end of the link, through which a screw is inserted loosely, so that it can freely slide therein.

, The practical operation of the abovedescribed device is as follows: The first, that which indicates the pressure of steam, is actuated by the steam-pressure exerted on a button inclosed in the part P, the steam being admitted through a pipe attached thereto instead of the screw Q, which is now only used in order to operate the mechanism by hand. The pressure of the steam forces upward the stem 0, referred to, connected to the lever D. This upward movement of the stem also forces up the spring B, also the lever D, and also the adjustable armFattached thereto by thelink E. This upward movement of the arm Fcauses the bow G to rotate the spindle to which the pointer h is fixed, thereby turning it around on the face of the dialR, Fig. 1, from zero, to which it points, to any number above on the scale, as the pressure of the steam may be, as 20, 40, 50, 60, 850., indicating the pounds pressure of steam by those figures. Let it be supposed that sixty pounds of steam is allowed by the inspector to be carried as the maximum pressure; this amount of pressure, as a consequence, will carry the pointer around to 60 on the dial. Now, in order that the inspector may know that no higher than sixty has been used, or may have been used, and the number of times that the steam has been in excess of that number of pounds is the purpose of the device above last described, and which it will do as follows: As the pressure-pointer h moves around from zero it carries with it the telltale pointer immediately beneath it by means of a point, m, projecting upward from the end of the tell-tale pointer, so that the pressure-pointer will come in contact with it as it moves around and upward, but not when the pointer returns back toward zero. The two pointers, as shown in the drawing, point to the zero. The lower or tell-tale pointer is not seen, as it is directly below the pressure one, but which, however, is indicated by the dotted line f. This pointer is carried along by the pointer h to 60, the prescribed degree of pressure, and where it will remain, as the spring-pawl 9, Fig. l, prevents it from returning when left by the pointer h. In the event that more than sixty pounds steam is used, then the pointer It will rise above the 60 and carry with it the pointer f, which will there remain, as it cannot return by reason of the pawl 9, thereby indicating that an excess of steam above 60 has been used once, but it may have been used in this degree of excess many times, but to no greater degree of excess but the tell-tale pointer indicates but one excess, as it is not moved further along by the pressure-hand unless the first excess is exceeded by a second, and so on. learn the number of times that the first degree of excess has been repeated, or any degree, the scale J is introduced, which operates as follows: As above said, let 60 be assumed as the maximum pressure, and that both of the pointers have been oneeto that number 5 now, should the pressure-hand go beyond 60, it will carry with it the tell-tale hand, which will remain there for the reason aforesaid. Now, in carryin g the tell-tale hand this distance the lever L is raised by means of the slotted link N, as the Therefore to adjustable arm F rises so far as to bring the pin to the extreme end of the slot; it will therefore lift up on the link, and thereby raise the end of the lever L. As the lever rises it pushes upward the pawl M, and as a consequence the sliding scale J goes with it by virtue of the engagement of the pawl in the notches on the edge of said scale. The ascent of the scale will be one degree or not'ch at a time, as the pawl is disengaged from the slide by a brake or push-01f, m, against which the end of the pawl will strike, and be thereby pushed from its engagement with the notch. The slide is prevented from falling down in consequence of the disengagement of the pawl therewith by means of the check 0, which holds up the slide when the pawl is not engaged with it. The adjustment of the pointers is such that on each time the pressure-hand goes beyond the 60, the assumed maximum pressure, the lever L will be actuated, thereby pushing up, as above described, the scale one not-ch, and one only, as the brake will push off the pawl from the slide when it is raised one degree or notch. It will be obvious that, by this means, the exact number of times that the pressure of steam is raised above the standard point it will be made known by the slide, although the distance above the standard point is not more than one degree, for the adj ustment of the link N and the pointer is so timed that the link and lever will be lifted by the arm E at the moment that the'pressurehand passes the point of maximum pressure, and which will be indicated by the scale and pointed out by the finger n, Fig. projecting from the side of the opening in the face of the dial-plate.

By the application of the above-described gage it will be impossible to carry steam above the standard point allowed without its being made known to the inspector, and not only the fact that steam has been used above said point, but also the number of times that it has been used in excess of the allowed maximum pressure.

Claim.

The pawl M, spring d, check 0, and brake on, as arranged in relation to and in combination with the sliding scale J, capable of returning to zero by its own weight, the whole operating substantially in the manner described, and for the purpose herein set forth.

JOHN P. HOLT.

W'itnesses:

W. H. BURRIDGE, JOHN H. BURRIDGE. 

